WHY DO YOU NEED TO CALCULATE YOUR 1RM?

Strength coaches set up programs with percentages based on your 1RM because they don’t know your actual strength level, but they know what percentages they want you to be using relative to your single-rep max. The calculator gives you all the relevant loads, which are done simply by multiplying the percentage by your 1RM.

One repetition maximum tests (1-RM) are popular for measuring muscle strength. It is a measure of the maximal weight a subject can lift with one repetition. Measuring 1RM has safety issues, so it is sometimes useful to estimate the 1RM using a calculator based on the number of times (greater than 1) that comeone can lift a certain weight.

Remember that each exercise has its own 1RM. Don’t use your back-squat 1RM to compute your front squat, or your underhand-grip bent-over row to determine the reverse-grip version—or any other movement. Keep in mind also that these are only estimates. The lower your rep count, the more accurate your 1RM estimate will be. Providing the weight you can do for three reps will give you a more accurate number than if you only know what you can do for 10.